Change default kwargs handle from warn to error

We have had this around for long enough to enable it.

Author: ChrisRackauckas

src/solve.jl

@@ -88,7 +88,7 @@ const allowedkeywords = (:dense,
     :linsolve_kwargs)
 
 const KWARGWARN_MESSAGE = """
-                          Unrecognized keyword arguments found. Future versions will error.
+                          Unrecognized keyword arguments found.
                           The only allowed keyword arguments to `solve` are:
                           $allowedkeywords
 
@@ -450,7 +450,7 @@ function Base.showerror(io::IO, e::IncompatibleMassMatrixError)
     println(io, TruncatedStacktraces.VERBOSE_MSG)
 end
 
-function init_call(_prob, args...; merge_callbacks = true, kwargshandle = KeywordArgWarn,
+function init_call(_prob, args...; merge_callbacks = true, kwargshandle = KeywordArgError,
     kwargs...)
     if has_kwargs(_prob)
         if merge_callbacks && haskey(_prob.kwargs, :callback) && haskey(kwargs, :callback)

test/downstream/kwarg_warn.jl

@@ -8,10 +8,9 @@ u0 = [1.0; 0.0; 0.0]
 tspan = (0.0, 100.0)
 prob = ODEProblem(lorenz, u0, tspan)
 @test_nowarn sol = solve(prob, Tsit5(), reltol = 1e-6)
-sol = solve(prob, Tsit5(), rel_tol = 1e-6)
+sol = solve(prob, Tsit5(), rel_tol = 1e-6, kwargshandle = DiffEqBase.KeywordArgWarn)
 @test_logs (:warn, DiffEqBase.KWARGWARN_MESSAGE) sol=solve(prob, Tsit5(), rel_tol = 1e-6)
-@test_throws DiffEqBase.CommonKwargError sol=solve(prob, Tsit5(), rel_tol = 1e-6,
-    kwargshandle = DiffEqBase.KeywordArgError)
+@test_throws DiffEqBase.CommonKwargError sol=solve(prob, Tsit5(), rel_tol = 1e-6)
 
-prob = ODEProblem(lorenz, u0, tspan, test = 2.0)
+prob = ODEProblem(lorenz, u0, tspan, test = 2.0, kwargshandle = DiffEqBase.KeywordArgWarn)
 @test_logs (:warn, DiffEqBase.KWARGWARN_MESSAGE) sol=solve(prob, Tsit5(), reltol = 1e-6)